[Elecraft] RE: IF Shift thoughts

[Don Wilhelm]

> -----Original Message-----
>
> Damned fine point... If IF shift is rarely useful for CW, and Keyer
> speed is never useful for SSB, then why bother using PF1/2 at all? Why
> not just use that knob as IF shift in modes "U"/"L" and Keyer speed in
> mode "C"?
>
-----------------------------------

Folks,

If 'IF Shift' is not useful for CW, then the K2 has something better than IF
Shift already.
Set up the SSB FL2 thru FL4 filters carefully so that FL2 is more narrow
than FL1 (the OP1 filter), then FL3 is about 200 Hz more narrow than FL2,
and FL4 is even more narrow than FL3.

Use Spectrogram (or equal) to determine the actual filter width - the
numbers displayed on the K2 will not be correct for these wide filters, and
set the low frequency corner of the passband at 300 Hz for all the filters.
Spectrogram will show the proper passband positioning.

When there is QRM on the high frequency side (audio frequency, it will be on
the high RF side for LSB and the low RF side for USB), just tapping the XFIL
button will cut the high audio frequency end and reduce the QRM.

It makes no sense to me to have the ability to cut the low frequency audio
end for SSB because by doing so will make the wanted signal unintelligible,
but the high frequency end can be cut drastically and still maintain
intelligibility - a 1600 Hz wide passband can contain adequate information
for a QSO.  Tuning with a narrow SSB filter becomes critical, so I recommend
tuning with the normal OP1 filter, then tap the XFIL button after the
desired station is tuned.  Try it, it works better for me than the SHIFT
control on my seldom used Yaesu.

To be repetitive, IF Shift will allow you to reduce either the audio highs
or the audio lows depending on which way you move it, but reducing the audio
lows is useless for SSB (the low frequency content in the 300 to 700 Hz
range must be maintained for intelligibility), you can achieve something
better with the present K2 filters.

73,
Don W3FPR